Add or update Data Model Schema for /requests API

[sahsisunny]

Description:
Update or add to the data model schema for the /requests API to accommodate new requirements and ensure alignment with the overall system architecture.

Requirements:

1. Modify the data model schema to support additional fields for new features.
2. Ensure data consistency and integrity with the existing system.
3. Update documentation to reflect any changes made to the data model.

Purpose:
Facilitate the seamless integration of new features and maintain consistency within the data model.